Pine Martens: Acrobats Of the Ancient Wildwood

Iconic, elusive and lithe, pine martens are one of Britain’s rarest native mammals. They scale trees effortlessly and if they fall, they twist in the air and land safely like a cat.  Dr. Orton investigates the treetop adventurers that once stalked our ancient wildwood and finds out how they could be making a recovery.

This is part of our rewilding series, a comprehensive guide to some of Britain’s rarest species with links to academic literature. For a quicker, more accessible read, you can read our posts about the nocturnal animals that live in our woods or our baby tawny owls!

Pine Martens (martes martes) are among Britain’s native mustelids. In the UK, they mainly live in Scotland, with very low numbers in England and Wales. 

Pine martens prefer to live in woodland and conifer plantations. They are forest specialists, although they can live in other landscapes, which is good news in Britain and Ireland where there has been significant deforestation. Sometimes pine martens will live in scrub, rocky areas, crags and other open country with some tree cover. Even so, pine martens are much more likely to be seen in trees than other mustelids.

Pine martens like to make their dens above ground, in natural cavities found in mature trees. They also use holes created by other creatures, like old squirrel dreys or bird nests. Pine martens are territorial and males might travel up to five miles in one night.

Although they are excellent climbers, pine martens find most of their food on the ground. Pine Martens are omnivorous and have a  very varied diet. They eat animals such as voles, mice, grey squirrels, rabbits and even hares. They also eat birds, reptiles and amphibians, invertebrates, fungi, nuts, eggs and carrion. Pine martens also eat fruit; during the summer, up to a third of the diet of Scottish pine martens might be made up of bilberries, which turns their scat blue.

Pine martens might remind you of weasels, ferrets, polecats and otters. That’s because they are mustelids, so they are similar in having round ears, short legs and long bodies. However, pine martens are bigger than many of these other animals; about the size of a house cat (males are bigger than females by a third). Even the American mink is slightly smaller than a pine marten, with much darker fur. 

They have chocolate-brown fur with a pale-yellow patch around their throats and long, lithe bodies with a long, bushy tail. Their fur is thicker and lighter in winter, and every pine marten has a uniquely shaped “bib,” that allows us to identify them.

Baby Pine Martens!

Baby pine martens are called kits!

Pine martens are solitary, coming together in the summer to mate (you can tell it’s pine marten mating season as they make yowls like a cat during this time). Due to delayed implantation, pine martens can mate in the summer but their babies won’t be born until March or April the following year.

In spring, the female will have a litter of up to five kits. The kits will emerge out of their dens after six weeks and will be independent by autumn. They will be ready to breed at two or three years old. Pine martens can live for up to ten years.

Pine Marten History

The pine marten was once the second most common carnivore in Britain. Today, it is one of the rarest. 

Pine martens have always been persecuted by humans. In the 1830s, Romantic poet John Clare wrote that the pine marten “hides in lonely shade.” Throughout the poem, the marten takes  refuge from poachers and “birdnesting boys” and is left “twisting round his den/Left free from boys and dogs and noisy men.”

The pine martens’ problems escalated in the late 1800s when the popularity of game shooting led to increased predator control. Other problems have been the loss of the martens’ woodland habitat and the fur industry.

By the early 20th century, pine martens were restricted to the Scottish Highlands and very small populations in Wales and northern England.

Bringing Back Pine Martens

 

Pine martens are now protected by the Wildlife and Countryside Act (1981) and their numbers have been slowly increasing. 

This is partly thanks to the reinforcement project undertaken by the Vincent Wildlife Trust, which released individual pine martens into an existing population to foster population size and genetic diversity. The project took 51 pine martens from Scotland’s healthy population and released them in forests in mid-Wales between 2015 and 2017.

The good news is that the translocated pine martens are established and breeding has been recorded every year since the project began!

Pine martens are also increasing in England. Seven male and eight female pine martens from Scotland were released in  Devon in the autumn of 2024 and are now living in the woods in  Dartmoor. The Two Moors Pine Project aims to  reintroduce and establish pine martens in Dartmoor and Exmoor National Parks.

Pine martens are expanding across the Forest of Dean in Gloucestershire. They hadn’t been seen for two hundred years, but 18 pine martens were translocated from Scotland in autumn 2019 by the Gloucestershire Wildlife Trust and Forestry England. Pine marten kits were born in spring 2020! It’s hoped that the martens will expand into neighbouring counties. 

In Shropshire, pine martens had been persecuted to extinction by the end of the 1800s, but there were reported sightings in the early twenty first century. The Pine Marten Project was set up by the Shropshire Mammal Group, which confirmed pine martens in Shropshire in 2015. Since then, over 20 individual pine martens have been seen, including juveniles.

The Vincent Wildlife Trust’s Pine Martin Recovery Plan, in collaboration with Natural England, recommended that Scotland’s donor population could support two more reintroduction projects  between 2021 and 2031, prioritising south-west England (Somerset and Devon) as they are close enough to Wales and Gloucestershire for there to be a gene flow

Squirrels and Pine Martens

As we saw in our post on Red Squirrels, studies from Scotland and  Ireland have found that pine martens could help in the conservation of red squirrels by reversing the spread of invasive grey squirrel populations. While pine martens prey on grey squirrels, red squirrels are able to avoid being eaten.

The Scottish study collected hair samples and used DNA forensics to identify individual pine martens. Then, spatial statistical models were used to reconstruct individual pine marten home ranges, quantify how much red and grey squirrels were exposed to these pine martens, and assess the effects of the pine martens on squirrel distribution. 

Wildlife biologist Dr. Emma Sheehy summarised the discoveries: “Clearly with the recovery of the native predator, the advantage has shifted in favour of the native prey species. It is really encouraging news both locally and in a global context, as it supports the concept that ecosystems with native predators can offer greater resistance to invasive species”.

Her colleague, Dr. Chris Sutherland, added, “…where pine marten activity was high, red squirrels took longer to use the feeders, which suggests red squirrels modify their behaviour to be more cautious when their natural predator is around. This type of behaviour is to be expected from species that have co-evolved together.”

These discoveries make sense when we consider evolutionary physiology: because of the slenderness of pine martens, they can pursue grey squirrels into small spaces like dreys that other predators cannot access. Red squirrels, on the other hand, have evolved to live alongside pine martens and have a greater awareness of the threat they pose. Their smaller size allows them to escape along thin branches that cannot support grey squirrels or pine martens.

It looks like pine marten recovery is good news for everyone. If livestock owners and game keepers are worried, the good news is that, because pine martens are afraid of are predators like foxes and raptors, they tend to keep away from open fields. Also, as they are very territorial and live in low densities, their numbers are self-limiting. The Vincent Wildlife Trust has advice for game and poultry keepers on living with pine martens.

On the Trail of Pine Martens

Pine martens are elusive and difficult to see. They are mostly nocturnal, and hunt at dusk or through the night, although it might be possible to see them during the day in summer.

Good places to visit include Coed Hafod y Llyn in Wales, or  Glen Quey, Glen Sherup, Geordie's Wood, Abriachan Wood, or Ledmore and Migdale in Scotland.

You’re more likely to identify pine marten presence by their sign. You can download the Vincent Wildlife Trust’s guide to identifying evidence of pine martens which will help you to identify pine marten sign.

You can look out for footprints, particularly following rain or snow. Like all mustelids, pine marten have five toes (unlike dogs and foxes, which have four).

Also look for pine marten dens. These will usually be in woodland habitats, although they can live in scrub, rocky areas and crags. Dens might be in tree cavities, squirrel dreys, wind-throw (trees uprooted by wind), purpose-built pine marten boxes and owl boxes. If you think you’ve found a pine marten den, look for bones of small mammals, feathers, and other remains.

Finally, pine martens mark their territories with scat, so look for it on forest trails or on boulders. Scats are coiled and might contain fur, feathers, bones or seeds. They might contain tiny, jagged teeth from voles – these voles can makeup forty percent of the martens’ diet. Remember that Scottish pine marten scat might be blue in summer due to all the bilberries!

In our next post, read about the return of the otter!

Find Out More

If you’re interested in conservation and wildlife, we have a blog series on British wildlife and a series on the people and wildlife of South Asia, from the altitudes of the Himalayas to the dense mangrove forests of Bangladesh!

We also offer online private tuition in our interdisciplinary course, Culture and Conservation, in which you can explore the links between our natural and cultural heritage and study wildlife and cultures from across the world! This is a template of a possible study route and can be combined, adapted, or designed from scratch to suit your interests and goals.

Dr. Orton will work with you to design a course of private tutorials tailored to your needs, ability and schedule. Click the link to find out what it’s like to work with her and contact us to find out more!

Do More

For those who would like to take action to preserve our wild spaces, there’s plenty you can do. If you're lucky enough to have some land, you could plant a wood from scratch (click the link to read about how we are planting our own native woodland). Even if you don’t have a big garden, there are plenty of things you can do to help biodiversity in your area. Why not put up a solitary bee nesting box or insect home, create a woodpile as a habitat for small creatures or leave small areas of your garden to go wild?

Think about your own area and how you can protect vulnerable but important parts of your own environment. You might even want to start your own project investigating the cultural importance of wildlife in your area. Dr. Orton works with independent scholars undertaking their own research for an independent project, people writing a book or simply those who have a personal interest. Click the link to find out what it’s like to work with her and contact us to get started!

Reach Out

We’d love to see what you’re doing to help wildlife in your area. Follow the Conservation highlight reel on the Orton Academy Instagram to see what we’re getting up to and tag us in to any snaps you put up!